Synthesis and characterization of a non-cytotoxic and biocompatible acrylamide grafted pullulan - Application in pH responsive controlled drug delivery

The aim of present study was to develop a pH responsive rate controlling polymer by acrylamide grafting onto pullulan. Grafting was performed using free radical induced microwave assisted irradiation technique using ceric ammonium nitrate as free radical inducer. Acrylamide grafted pullulan (Aam-g-pull) was characterized by Fourier transform infrared spectroscopy, solid state 13C nuclear magnetic resonance and field emission scanning electron microscopy. In vitro enzymatic degradation of Aam-g-pull showed degradation of 22.45% after 8 h with degradation rate constant (k) of 0.019 min−1. In vitro cytotoxicity test did not show cell viability below 80% on HepG2 cell line. Pirfenidone tablets were prepared by utilizing wet granulation method using Aam-g-pull as the only rate controlling polymer. The tablets were characterized in terms of in-process quality control parameters like weight variation, hardness, assay, and in vitro dissolution study. The dissolution study showed that the cumulative drug release in phosphate buffer pH 6.8 (rel3 h = 44.12 ± 0.56%) got a significant jump as compared to the release in 0.1 N hydrochloric acid (rel2 h = 26.78 ± 0.23%), confirming the material to be pH responsive. Aam-g-pull can be used as pH responsive rate controlling polymer.